Method of preparing pyrites fines for desulfurization.



sessing the characteristics specified.

UNITED STATES PAEENT OFFICE.

PlERRE DE PEYSTER :RICKETTS AND TOM COBB KING, OF NEW YORK, N. Y;, ASSIGNOR S TO NATIONAL METALLURGIC COMPANY, OF JERSEY CITY, NEW JERSEY, A CORPORATION OF NEW JERSEY.

METHOD OF PREPARING PYBITE S FINES FOR DESULFURIZATION.

Specification of Letters Patent.

Patented Jul as, loos.

Original application filed May 4, 1905, Serial No. 258,895. Divided and this application filed November 20, 1905.

- v Serial No. 288,162.

To all whom it may concern: in

Be it known that we, PIERRE DE PEYsTER RIoKErTs and ToM COBB KING, both citizens of the United Statesfresiding at New York, in the county of New York and State of New York, have jointly discovered or invented a new and useful Improvement in Methods of Preparing Pyrites Fines for Desulfurization, of which the following isia description. Our invention relates to method of preparing and treating pyrites fines for usein urners or'kil'ns for desulfurizing.

The object of our invention is to produce from pyritesfines, hardened, artificially formed lumps, shapes or bodies of pyrites, free from extraneous harmful binding ingreclients, and possessing the following features or characteristics, viz: density and hardness sufficient to prevent crumblingor crush-.

ing in shipment or. handling, substantially anhydrous in character, therefore not liable to disintegrate when brought in contact with moisture, not liable during burning to create a dust like material liable to contaminate the acid produced therefrom, and finally possessing the characteristic of burning freely in an ordinary burner or kiln. We accomplish this object by means of the method or process of treating-pyrites fines which consists of mixing with. the fines a requisite quantity or percentum of fusible sulfid Fe S sulfur and iron, or other sulfur compound, which when made viscous or liquid, as hereinafter more specifically described, permeates the mass cohering the particles thereof and when 0001 converting the same into a solid body, pos- Pyrites fines exist in large uantities and are constantly being produce as there are many deposits of ore in which the ore is so friable and crumbly that the least handling produces fines.

Heretofore, so far as we are aware, the: use

of pyrites fines in the manufacture of sulfuric acid-has been attended with seriousof dust like material carried over from the heretofore herein kilns or burners into the fines and Glover towers, and finally, owing to the pulverulent nature of the material, the difficulty of maintaining free combustion, and of preventing the complete cessation of combustion (which occurs quite fre uently unless prevented by the use of specia burners).

It was quite generally recognized that the best possible way to utilize or pre are the fines for desulfurizing was to form t fe-same into lumps, and numerous efforts have beenmade to oohere or form F e,S (pyrrhotite) or ferrous sulfid, FeS,and

like s stances, or with the fines we mixsulfur and iron, and subject the mixture to heat, without access of air, or in a reducing atmosphere thereby taking advantage of the fusing temperature of the sulfurc'ompounds which are lower than=the fusing temperature of the pyrites fines. The sulfur compounds become liqpid or viscous, de ending upon the temperature to which t ey are heated (at 114 centigrade sulfur is liquid or:

mobile; at 230 centigr'ade sulfur is viscous;-

at 800 centigrade sulfur becomes a gas) and permeate or are diffused'throu h the material and binds the same into a co 'erent mass when the mixture is cooled, the sulfur" or compounds becoming S0l1d of the sulfide when cold. In the ractice of our invention to produce the s apes desired, We take'thegiyrites fines plus the sulfur compounds an place the mixture: in a retort or mold which can be closed and apply heat thereto externally,

,adding pressureifgdesired, until the binding materia fuses throughoutthe mass, using only sufiicient heat to soften or liquefy the sulfur compounds without liquefying "the ioo.

and in this form heated in a closed vessel or I in a reducing atmosphere until the sulfur in the sulfids or compounds becomes viscous or liquid, then by cooling as heretofore, described solidify the same.

We are aware that lime and magnesia have been employed to bind or cohere the fines into lumps or bodies of sufiicient hardness to bear transportation, but the mixture of the lime and magnesia not only impaired the burning capacity of the pyrites, but also introduced therein a foreign element which at certain temperatures served to, effect stable compounds with the sulfur, thus reducing the percentum of sulfur in the lump or body formed.

We are also aware that ferrous and lead sulfates have been used as binders, producing a product sufiiciently firm or hard for transportation. The use of these materials as binders was objectionable, however, inasmuch as their use introduced foreign materials, which not only impeded the free burning of the pyrites, but what is more objectionable, the said materials being absorbents of moisture, prevented the formation of a lum or shape, anhydrous in character, the pro uced body disintegrating when exposed to damp Weather or when brought in contact with moisture. Another objection to these materials as binders is that the absorption of moisture interferes with the easy and satiss factory burning of the product for the pur g pose of desulfurizing.

l We claim as our invention and desire to sccure by Letters Patent:

ing pyrites finesfor desulfurization, w rich consists in adding to the fines and mixing therewith fusible sulfur compounds subject ing the mixture to heat sufiicient to liquefy ing conditions eing maintained during he application of the heat.

2. The herein described method of pre ):u'- ing pyrites fines for desulfurization which consists in adding to the fines and in timatcly mixing therewith a fusible sulfid, subjecting themixture to the requisite heat in a re lucing'atnios here, then cooling.

3. The erein described method of pre mring pyrites fines for desulfurizatiou, which consists in adding to and mixing with the fines a fusible sulfur com )ound, subjecting the mixture to heat sufiicient to liquefy the sulfur compound whereby the same 1s caused to cohere and bind the mixture, then by pressure com ress the same into desirable shape, and final ycooling.

In testimony whereof, We have hereunto signed our names in the presence of two subscribing witnesses.

Plllllltll DE PEYSTER' RICKETTS, TOM COBB KlNG. In the presence of Gno. R. A. Hroxnrrs,

CHARLES F. GRILL.

1. The herein described method of preparthe sulfur com ound in the mixture, reduc-- 

